The poetic beauty of Betelgeuse: A story of our origins

I always feel a bit nerdy when I say that I have a favourite star. But then again, I am. The star's name is Betelgeuse and is one of the largest and brightest stars we are yet to observe with a size almost a thousand and a half greater than our sun. But I'm not going to overwhelm you with facts. Instead, I want to share with you a little story of why I love this star which I hope will leave you with a smile at the very end.

Picture of Betelgeuse captured by the Atacama Large Millimeter/submillimeter Array (ALMA)
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Growing up in Norway, I had a good opportunity to stargaze as night would come early in winter. Indeed, for much of November to January, it would be rather dark already at 3 or 4 pm, opening up the heavens for the eyes to enjoy! Having a dog also meant I would usually go out for a walk every evening. During the winter, this would typically mean taking her out to a little grass-covered field close to our house where I would let her do her thing whilst I could simply lean back and look up at the sky.

I’ve always treasured the ability to spend at least half an hour at the end of every day just calming the mind. Whether you’re working, studying, or worrying about the fact that you're currently doing neither, allowing yourself to calm down before going to bed has many health benefits.
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Anyways, the winter also happened to be the time when Betelgeuse is visible every night in the northern hemisphere. I would therefore always be quick to locate it whenever I looked up during a starry night. But why is this star so special to me? One simple reason: It is the only star (at least from the set of stars visible in Norway) that is visibly red to the naked eye. Most people do not even recognize this. The stars more or less look the same to them. Some brighter than others, but they still usually appear white. Not Betelgeuse. So how come it is red? And why is that so special? Well, it's about to die the most violent death in the Universe.

Stars turn red when they are at the end of their long lifecycles. A star is basically a huge nuclear reactor where Hydrogen is brought together by gravity. With increasing pressures, the Star turns increasingly hot, allowing fusion to occur. Here, heavier elements are formed including Carbon, Oxygen, and Nitrogen, among others. Because these new-formed elements are heavier, the force of gravity pulls even stronger. This then heats up the star even more, and so the heavier elements also begin to fuse, creating Iron which is then collected at the very centre. So here is where it gets interesting: We know that there were no other elements but Hydrogen and Helium at the time the first stars were formed. The stars are also, to our knowledge, the only place in the Universe where these elements can be naturally formed, as no other places produce the necessary energy levels.

Atomic overview of the elemental composition of a Star
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These facts may be cool enough on their own for someone with an interest in science, now you know how heavier elements are created! However, they also carry some interesting implications. It means that the atoms that make up our bodies, from the tissue in our brains to the blood running through our veins, have all been, at some point in cosmic history, at the centre of a star. A dying star in fact, as the nuclear fusion can only last for as long as there is more Hydrogen to fuse, at which point, the Star collapses on itself, expands, and explodes. Indeed, you are likely to carry the remnants of hundreds or thousands of different stars who have once exploded and scattered the heavier elements out into the Universe. You can imagine how these elements have spent millions and billions of years travelling through space, only to come together for a brief moment, to produce you.

Illustration of a supernova from an article titled "Should We Be Preparing for the Explosion of Betelgeuse Supernova?"
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Considering the high number of atoms within each human being, it is also certain that you, who are reading this blog, have atoms in your body that have belonged to the same star as atoms within me. This is indeed true for anyone you will ever know, and anyone who has ever existed. To me this is probably the most beautiful thing we have discovered in astronomy, and it has had a real effect on how I choose to see other people.

So the next time you look at a friend, a family member, or indeed a stranger, you can reflect on the fact that at some deep level, you are all connected. It is by no means stretching it too far to say that hundreds of stars had to die the most violent death known to man (the supernova) in order for you to be here.

So when I’m out there a winter night looking up at Betelgeuse, I reflect on this fact and imagine its beautiful meaning. So perhaps you should look up at what time of year Betelgeuse is visible where you live, and go out to have a look yourself! Then you can remember, that you are indeed made of stardust!

(Or nuclear waste, technically that is also correct)